Lipidome of extracellular vesicles from Giardia lamblia.

Extracellular vesicles (EVs) (exossomes, microvesicles and apoptotic bodies) have been well acknowledged as mediators of intercellular communications in prokaryotes and eukaryotes. Lipids are essential molecular components of EVs but at the moment the knowledge about the lipid composition and the function of lipids in EVs is limited and as for now none lipidomic studies in Giardia EVs was described. Therefore, the focus of the current study was to conduct, for the first time, the characterization of the polar lipidome, namely phospholipid and sphingolipid profiles of G. lamblia trophozoites, microvesicles (MVs) and exosomes, using C18-Liquid Chromatography-Mass Spectrometry (C18-LC-MS) and Tandem Mass Spectrometry (MS/MS). A total of 162 lipid species were identified and semi-quantified, in the trophozoites, or in the MVs and exosomes belonging to 8 lipid classes, including the phospholipid classes phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylinositol (PI), cardiolipins (CL), the sphingolipid classes sphingomyelin (SM) and ceramides (Cer), and cholesterol (ST), and 3 lipid subclasses that include lyso PC (LPC), lyso PE (LPE) and lyso PG (LPG), but showing different abundances. This work also identified, for the first time, in G. lamblia trophozoites, the lipid classes CL, Cer and ST and subclasses of LPC, LPE and LPG. Univariate and multivariate analysis showed clear discrimination of lipid profiles between trophozoite, exosomes and MVs. The principal component analysis (PCA) plot of the lipidomics dataset showed clear discrimination between the three groups. Future studies focused on the composition and functional properties of Giardia EVs may prove crucial to understand the role of lipids in host-parasite communication, and to identify new targets that could be exploited to develop novel classes of drugs to treat giardiasis.

Uso de secnidazol y homeopatía para el control de giardiasis en perros / Use of secnidazole and homeopathy for giardiasis control in dogs

RESUMEN Los perros con infecciones por Giardia tienen diarrea que persiste durante días, incluso después del tratamiento. Manejamos la giardiasis canina usando dos enfoques distintos: tratamiento con el secnidazol antiprotozoario solo; y secnidazol más un producto homeopático indicado para el control de la diarrea en perros. Tratamiento I: Diez perros beagle mostraron signos clínicos de diarrea severa. Sus heces revelaron una gran cantidad de quistes compatibles con Giardia sp. Por lo tanto, tratamos a los perros con secnidazol (10 mg/kg, dosis única) por vía oral. Cinco días después del tratamiento, todos los perros fueron negativos para Giardia spp. Tratamiento II: Tres meses después, los mismos diez Beagles nuevamente presentaron diarrea. Se recogieron las heces, revelando Giardia sp. en todos los perros. Esta vez, los tratamos con un antiprotozoo (secnidazol, dosis de 10 mg/kg) combinado con un medicamento homeopático comercial para el control de la diarrea (dosis de 3 g/animal a intervalos de 12 h). Descubrimos que se necesitaban de tres a cinco dosis homeopáticas para lograr puntajes fecales normales en todos los perros. Después de 5 días de tratamiento, las muestras de heces tuvieron una consistencia normal y fueron negativas para Giardia. Este es el primer registro de uso de secnidazol para el control de la giardiasis canina asociado con homeopáticos para evitar la diarrea.

ABSTRACT Dogs with Giardia infections have diarrhea that persists for days, even after treatment. We managed canine giardiasis using two distinct approaches: treatment with the antiprotozoan secnidazole alone; and secnidazole plus a homeopathic product that is indicated for control of diarrhea in dogs. Treatment I: Ten beagle dogs showed clinical signs of severe diarrhea. Their feces revealed large numbers of cysts consistent with Giardia sp. Therefore, we treated the dogs with secnidazole (10 mg/kg, single dose) given orally. Five days after treatment, all dogs were negative for Giardia spp. Treatment II: Three months later, the same ten Beagles again presented with diarrhea. Feces were collected, revealing Giardia sp. in all dogs. This time, we treated them with an antiprotozoan (secnidazole, 10 mg/kg dose) combined with a commercial homeopathic drug for diarrhea control (3 g dose/animal at 12 h interval). We found that three to five homeopathic doses were needed to achieve normal fecal scores in all dogs. After 5 days of treatment, stool samples had normal consistency and were negative for Giardia. This is the first record of using secnidazole to control canine giardiasis associated with homeopathic drugs to prevent diarrhea.

The Tail of Kinesin-14a in Giardia Is a Dual Regulator of Motility.

Kinesin-14s are microtubule-based motor proteins that play important roles in mitotic spindle assembly [1]. Ncd-type kinesin-14s are a subset of kinesin-14 motors that exist as homodimers with an N-terminal microtubule-binding tail, a coiled-coil central stalk (central stalk), a neck, and two identical C-terminal motor domains. To date, no Ncd-type kinesin-14 has been found to naturally exhibit long-distance minus-end-directed processive motility on single microtubules as individual homodimers. Here, we show that GiKIN14a from Giardia intestinalis [2] is an unconventional Ncd-type kinesin-14 that uses its N-terminal microtubule-binding tail to achieve minus-end-directed processivity on single microtubules over micrometer distances as a homodimer. We further find that although truncation of the N-terminal tail greatly reduces GiKIN14a processivity, the resulting tailless construct GiKIN14a-Δtail is still a minimally processive motor and moves its center of mass via discrete 8-nm steps on the microtubule. In addition, full-length GiKIN14a has significantly higher stepping and ATP hydrolysis rates than does GiKIN14a-Δtail. Inserting a flexible polypeptide linker into the central stalk of full-length GiKIN14a nearly reduces its ATP hydrolysis rate to that of GiKIN14a-Δtail. Collectively, our results reveal that the N-terminal tail of GiKIN14a is a de facto dual regulator of motility and reinforce the notion of the central stalk as a key mechanical determinant of kinesin-14 motility [3].

Ascorbic acid potentiates the Giardia duodenalis growth inhibitory activity of pure Terminalia ferdinandiana Exell compounds.

Giardiasis, one of the most common causes of diarrhoeal disease, is caused by gastrointestinal protozoal parasites of the genus Giardia. Metronidazole is the most commonly used drug to treat giardiasis. However, metronidazole resistance is increasingly common, making the development of new anti-giardial drugs a high priority. A panel of 11 compounds previously identified in T. ferdinandiana fruit extracts were investigated for the ability to inhibit G. duodenalis proliferation. Eight of the 11 compounds inhibited the growth of all three G. duodenalis strains. 2,3-Dihydroxyphenyl B-D-glucopyranosiduronic acid (DPGA) was the most potent anti-giardial compound, with IC50 values as low as 126 µM (38 µg/mL). Notably, DPGA inhibited a metronidazole-resistant G. duodenalis strain with similar activity as determined for the metronidazole-sensitive strains. Furthermore, the activity of DPGA was greatly potentiated when it was tested in combination with ascorbic acid, to approximately 17 µM (5 µg/mL) for the metronidazole-sensitive G. duodenalis strains and 40 µM (12 mg/mL) for the resistant strain. The T. ferdinandiana tannins (gallic acid and chebulic acid) were moderate inhibitors of G. duodenalis growth when tested in combination with ascorbic acid, although they had only low levels of activity when tested alone. All of the tested compounds (and their combinations with ascorbic acid) displayed low toxic effects and all compounds are conformed to Lipinski's rules of 5 with few violations, indicating their potential as drug leads and chemotherapies for the treatment and prevention of giardiasis.

Acute phase response in organic lambs associated with colostrum serum amyloid A, weight gain, and Cryptosporidium and Giardia infections.

In neonatal period, lamb's immune system goes through rapid adaptation to the extra-uterine environment. Success of this process can influence the animal's future performance and, thus, the quantitative assessment of it would greatly benefit sheep producers. The current study was conducted to investigate the acute phase response (APR) (measured through serum amyloid A (SAA), haptoglobin (Hp) and albumin (ALB)) in relation to later life growth (measured at 122 days of age), and naturally occurring Cryptosporidium and Giardia infections in neonatal lambs grown in organic farm. Serum (n = 692) and faecal (n = 141) samples were collected from 269 lambs in their first 3 weeks of life. The ewes' colostrum (n = 181) SAA concentrations were positively associated with the lambs' serum SAA and Hp concentrations at 2 to 4 days of age. Hp and ALB concentrations at the second week of age were positively associated with the growth rate at 122 days of age. Lamb serum globulin (GLOB) concentrations and Cryptosporidium-positive faecal samples were negatively associated at the second and third weeks of life. These findings suggest the importance of interactions between the immune system and environmental factors at the second week of the lambs' lives and its association with future performance.

Anti-giardia activity and acute toxicity of a methanol extract of Senna racemosa bark.

ETHNOPHARMACOLOGICAL RELEVANCE: Senna racemosa (Mill.) H.S. Irwin & Barneby (syn. Cassia racemosa Mill.) is a plant used in traditional Mayamedicinal practices to treat diarrhea. A methanol extract of S. racemosa bark has been shown to have in vitro activity against Giardia intestinalis. No studies of its efficacy and toxicity in in vivo models have been done. The present study objective was to analyze the activity of this methanol extract of S. racemosa bark against Giardia intestinalis trophozoites in experimentally infected mice, and evaluate its toxicological effects in rats. MATERIAL AND METHODS: S. racemosa was collected in Merida, Yucatan, Mexico (21°58'N, 89°36'W) in June 2005. The bark methanol extract was obtained and high performance liquid chromatography (HPLC-DAD) was used to generate a constituent profile. In vivo anti-giardia activity was assayed with an experimental model of G. intestinalis infection in neonatal CD-1 mice. Nine doses ranging from 0.25-15mg extract/kg body weight were tested to determine the dose required to kill 50% of the trophozoites (ED50). An acute toxicity assay was run in which one of four single doses (200, 1000, 2000 and3000mg/kg body weight) was orally administered to adult Wistar rats. Animal weight, death rates, toxic effects and behavioral parameters were observed over a 14-d period. They were then euthanized and a necropsy performed. RESULTS: The S. racemosa bark extract inhibited growth of G. intestinalis (ED50=1.14mg/Kg) in neonatal CD-1 mice. No toxic or lethal effects were observed even at the highest dosage (3000mg/Kg), and neither were signs of toxicity observed in internal organs. The active compounds chrysophanol and physcion were present in the extract at a 1.76 ratio. CONCLUSIONS: The results strongly support traditional use of S. racemosa bark for treatment of diarrhea caused by Giardia intestinalis infection.

Prebiotic inulin supplementation modulates the immune response and restores gut morphology in Giardia duodenalis-infected malnourished mice.

Malnutrition induces a state of growth retardation and immunologic depression, enhancing the host susceptibility to various infections. In the present study, it was observed that prebiotic supplementation either prior or simultaneously with Giardia infection in malnourished mice significantly reduced the severity of giardiasis and increased the body and small intestine mass, along with increased lactobacilli counts in faeces compared with malnourished-Giardia-infected mice. More specifically, prebiotic supplementation significantly increased the levels of anti-giardial IgG and IgA antibodies and anti-inflammatory cytokines IL-6 and IL-10 and reduced the pro-inflammatory cytokine TNF-α, along with increased levels of nitric oxide in both the serum and intestinal fluid of malnourished-prebiotic-Giardia-infected mice compared with malnourished-Giardia-infected mice. Histopathology and scanning electron microscopy of the small intestine also revealed less cellular and mucosal damage in the microvilli of prebiotic-supplemented malnourished-Giardia-infected mice compared with severely damaged mummified and blunted villi of malnourished-Giardia-infected mice. This is the first study to report that prebiotic supplementation modulated the gut morphology and improved the immune status even in malnourished-Giardia-infected mice.

Anti-giardial therapeutic potential of dichloromethane extracts of Zingiber officinale and Curcuma longa in vitro and in vivo.

Giardiosis is one of the common parasitic diarrhoea in humans, especially in children, worldwide. Many drugs are used for its treatment, but there is evidence of drug resistance, insufficient efficacy and unpleasant side effects. Natural products are good candidates for discovering more effective anti-giardial compounds. This study evaluated the activity of extracts of Zingiber officinale (ginger) and Curcuma longa (curcumin) against Giardia lamblia in vitro and in vivo. Giardia cyst suspension was prepared from children faecal specimens. For the in vitro experiment, 1, 10 and 50 mg/mL dichloromethane extracts of ginger and curcumin separately were incubated with Giardia cysts for 5, 10, 30 and 60 min. The viability was distinguished by 0.1 % eosin and a haemocytometer. For the in vivo experiments, Balb/c mice were infected with Giardia cyst suspension containing 10,000 cysts/mL. Infected mice were administered 10 and 20 mg kg(-1) day(-1) ginger and curcumin extracts separately for 7 days post-infection. The effectiveness of the extracts was evaluated by faecal cyst and intestinal trophozoite counts and histopathological examination of the small intestine. In vitro ginger extract had a higher significant effect on cyst viability than curcumin, in a dose- and time-dependent manner. In vivo ginger (more effective) and curcumin extracts significantly treated infected mice, and this was evidenced by the faecal cyst and intestinal trophozoite counts reduction, in addition to evident improvement of intestinal mucosal damages induced by Giardia infection. Z. officinale and C. longa extracts may represent effective and natural therapeutic alternatives with low side effects and without drug resistance in the treatment of giardiosis.

Marked antigiardial activity of Yucca baccata extracts: a potential natural alternative for treating protozoan infections.

Human giardiosis is a public health problem in Mexico, where the national prevalence was estimated to be up to 68%. Misuse of antiprotozoal drugs may result in low effectiveness and undesirable side effects. Research on natural products is a good strategy for discovering more effective antiparasitic compounds. This study evaluated the antigiardial activity of extracts of Yucca baccata, which is native to northwestern Mexico. Forty-two gerbils (females) were weighed and orally inoculated with 5 × 10(6) Giardia trophozoites. Two gerbils were selected at random to confirm infection. Forty living gerbils were randomly allocated into 5 treatment groups (8 per group). Gerbils were randomly assigned to be treated with 24.4 mg/mL, 12.2 mg/mL, and 6.1 mg/mL of extracts, metronidazole (2 mg/mL) or PBS, which were intragastrically administered once per day for 3 days. Nine gerbils died during the study course. On day 10 postinfection, gerbils were euthanized and trophozoites were quantified. Yucca extracts reduced, albeit not significantly, the trophozoite counts in the duodenum segment. Only the high-extract concentration significantly reduced the trophozoite counts in the proximal segment and it was similar to that of metronidazole. Extracts of Y. baccata may represent an effective and natural therapeutic alternative for human giardiosis.

Using participatory epidemiology to assess factors contributing to common enteric pathogens in Ontario: results from a workshop held at the Ontario Veterinary College, University of Guelph, Ontario.

BACKGROUND: Common enteric pathogens that cause gastrointestinal illness are transmitted to humans through food, water or direct contact. This poses a significant concern to public health as enteric pathogens can cause disease in a large number of people, and cost a substantial amount to treat and prevent. In order to gain a better understanding of the occurrence of enteric disease in Ontario, this study explored public health professionals' perceptions of major contributing factors for common enteric pathogens. METHODS: A case study was conducted as part of a two week training workshop in Participatory Epidemiology held at the Ontario Veterinary College, University of Guelph, in May 2013. Eight semi-structured interviews and four focus groups were conducted with representatives from the Public Health Agency of Canada, the University of Guelph, and three health regions in Southern Ontario. Written notes and pictures captured the qualitative information provided. Results were then analyzed using the mixed methods techniques of triangulation, convergence, and paradox. RESULTS: A total of fifty factors that contribute to enteric disease were identified across all interviews and focus groups. These contributing factors were grouped into key themes (travel, food handling, industry (farm-to-fork), water, geography, demographics, and behaviours) and were categorized as either a risk factor or susceptibility factor. Informants emphasized the complex relationships between the identified factors, and highlighted why these complexities make it difficult to determine where and how a person most likely acquired an enteric pathogen. Workshop participants observed differences in the type and quality of information collected during interviews and focus groups; we hypothesize that this may be attributed to the dynamics between group members (i.e. focus group discussions) as opposed to one-on-one interviews. CONCLUSIONS: The information gathered will serve as a starting point to further explore contributing factors for common enteric pathogens. The identified complexities would be best explored by conducting additional surveillance, as well as interviews and focus groups with a more diverse group of stakeholders. This type of qualitative study can enhance knowledge of enteric pathogen surveillance and contribute to the development of resources and initiatives to holistically address the occurrence of gastrointestinal illness.

Iron-sulphur clusters, their biosynthesis, and biological functions in protozoan parasites.

Fe-S clusters are ensembles of sulphide-linked di-, tri-, and tetra-iron centres of a variety of metalloproteins that play important roles in reduction and oxidation of mitochondrial electron transport, energy metabolism, regulation of gene expression, cell survival, nitrogen fixation, and numerous other metabolic pathways. The Fe-S clusters are assembled by one of four distinct systems: NIF, SUF, ISC, and CIA machineries. The ISC machinery is a house-keeping system conserved widely from prokaryotes to higher eukaryotes, while the other systems are present in a limited range of organisms and play supplementary roles under certain conditions such as stress. Fe-S cluster-containing proteins and the components required for Fe-S cluster biosynthesis are modulated under stress conditions, drug resistance, and developmental stages. It is also known that a defect in Fe-S proteins and Fe-S cluster biogenesis leads to many genetic disorders in humans, which indicates the importance of the systems. In this review, we describe the biological and physiological significance of Fe-S cluster-containing proteins and their biosynthesis in parasitic protozoa including Plasmodium, Trypanosoma, Leishmania, Giardia, Trichomonas, Entamoeba, Cryptosporidium, Blastocystis, and microsporidia. We also discuss the roles of Fe-S cluster biosynthesis in proliferation, differentiation, and stress response in protozoan parasites. The heterogeneity of the systems and the compartmentalization of Fe-S cluster biogenesis in the protozoan parasites likely reflect divergent evolution under highly diverse environmental niches, and influence their parasitic lifestyle and pathogenesis. Finally, both Fe-S cluster-containing proteins and their biosynthetic machinery in protozoan parasites are remarkably different from those in their mammalian hosts. Thus, they represent a rational target for the development of novel chemotherapeutic and prophylactic agents against protozoan infections.

Wastewater infrastructure for small cities in an urbanizing world: integrating protection of human health and the environment with resource recovery and food security.

The majority of population growth in developing countries will occur in small cities closely linked to agricultural zones, with poor access to water and sanitation. Wastewater management priorities in these regions will be different from those in larger cities and developed countries. Two wastewater treatment systems in Bolivia, one with an upflow anaerobic sludge blanket (UASB) reactor and polishing ponds, the other with three stabilization ponds, are assessed to determine their resource recovery potential. The UASB reactor produces biogas with 500-650 MJ per day. In six months, both systems discharge wastewater with the same mass of nutrients as fertilizers used to produce crops containing 10-75 days' worth of the recommended food energy intake for each person using the system. Both systems also discharge detectable levels of helminth eggs, Giardia cysts, and Cryptosporidium oocysts, but the UASB reactor system discharges higher concentrations, implying limited reuse potential. From a regional management standpoint, small cities should not expend resources to treat wastewater to levels suitable for discharge into surface waters. Rather, they should focus on removing pathogens to reclaim water and nutrients. Biogas recovery may be a priority that should be subservient to water and nutrient recovery in these settings.

Determining potential indicators of Cryptosporidium oocysts throughout the wastewater treatment process.

Most research on wastewater treatment efficiency compliance focuses on physicochemical and microbial indicators; however, very little emphasis has been placed so far on determining suitable indicator organisms to predict the discharge level of pathogens from treatment plants. In this study, raw wastewater, activated sludge, and the resulting final effluents and biosolids in four municipal wastewater treatment plants (WWTPs A, B, C and D) were seasonally investigated for human-virulent water-borne pathogens Cryptosporidium parvum/hominis and Giardia duodenalis, and microsporidia (e.g. Encephalitozoon hellem, E. intestinalis, and Enterocytozoon bieneusi) between 2008 and 2009. A suite of potential microbial indicators for human-virulent protozoa and microsporidia was also determined. A combination of multiple fluorescent in situ hybridization and immunofluorescent antibody assays were applied to detect Cryptosporidium oocysts, Giardia cysts, and microsporidian spores. Escherichia coli, enterococci and Clostridium perfringens spores were cultivated in selective media. Positive correlations were found between the abundance of enterococci and E. coli and abundance of Cryptosporidium oocysts (r(s) > 0.47, p < 0.01) and Giardia cysts (r(s) > 0.44, p < 0.01) at WWTPs A-D. Cryptosporidium perfringens spores were positively correlated to Cryptosporidium oocysts (r(s) = 0.40, p < 0.01) and Giardia cysts (r(s) = 0.46, p < 0.01). There was a strong positive correlation between abundance of Giardia cysts and that of Cryptosporidium oocysts (r(s) > 0.89, p < 0.01). To sum up, a suite of faecal indicator bacteria can be used as indicators for the presence of Cryptosporidium oocysts and Giardia cysts in these activated-sludge systems (WWTPs A, B and C). Overall, Giardia duodenalis was noted to be the best Cryptosporidium indicator for human health in the community-based influent wastewater and throughout the treatment process.

Land-use change and emerging public health risks in New Zealand: assessing Giardia risks.

Agriculture is key to New Zealand's economy with land-use conversions in response to market forces occurring regularly, like that of recent dairy intensification throughout the country. However, land-use conversion can occasionally result in unexpected and significant consequences for public health that need to be accurately estimated and subsequently managed accordingly. For example, dairy cattle have high Giardia prevalence in New Zealand and identical strains from infected humans and cattle located in the same geographical region have recently been reported. Thus, the high rates of human infections in New Zealand compared to similar socioeconomic countries caused by the waterborne pathogen Giardia are particularly concerning given the increasing dairy cattle populations on the landscape. However, the ability of traditional, evidence-based, epidemiological approaches to detect such causal relationships between land-use and Giardia infections is limited given the many possible indirect links between the two, in turn highlighting the need to develop appropriate risk assessment techniques. As such, the general requirements for and development of risk assessment frameworks to evaluate the likelihood of public health risks from waterborne pathogens are introduced and explored using Giardia in New Zealand as an example. Specifically, the importance of recent advances in Giardia-based knowledge, the incorporation of such data into existing risk assessment frameworks and the influence of remaining research gaps are each discussed for expanding currently available risk assessment tools. Not surprisingly, the availability of appropriate risk assessment tools for agencies responsible for public health and environmental management would ensure the public health risks for Giardia resulting from land-use change could be quantified holistically and strategies subsequently developed through active agency communication to minimise such risks.

Infectivity of Giardia duodenalis Assemblages A and E for the gerbil and axenisation of duodenal trophozoites.

Establishing in vitro cultures of Giardia duodenalis trophozoites from faecal cysts remains very difficult due to poor excystation and bacterial contamination. This study investigated an alternative approach starting from duodenal trophozoites of gerbils that were artificially infected with field isolates from humans (Assemblages A and B) and cattle (Assemblage E and mixed E/A). Gerbil infection was successful for Assemblages A (1/1) and B (1/3) from humans, and for E (1/2) and mixed E/A (6/6) from cattle. Despite the fact that some isolates subsequently failed or were difficult to establish in vitro, several Assemblage A and Assemblage E in vitro trophozoite cultures were successful, however, subsequent cloning required adaptation of the standard TYI-S-33 medium whereby different medium supplements were required for promoting growth. Excess of l-cysteine (2mg/ml) and ascorbic acid (0.2mg/ml) supported cloning of Assemblage A, while l-glutathione (7.8 mg/ml) was required for Assemblage E. This is a first description of in vitro axenisation of Assemblage E trophozoites from cattle.

[The efficacy of ecdystene versus metronidazole in the treatment of lambliasis].

Ecdisten, the drug designed on the basis of the phytoecdisteroid ecdisterone isolated from Rhaponticum carthamoides, was used in the treatment of first diagnosed (primary) and persistent (resistant to traditional lambliacides) lambliasis. A control group received metronidazole. Daily parasitological monitoring of lamblia elimination while treating with ecdisten in a daily dose of 20 mg for 10 days indicated the absence of lamblia in 70% of the patients with primary lambliasis on days 3 to 5; in the remaining 30%, parasitic elimination was accomplished on days 6-7 of treatment. In the patients with persistent lambliasis, the parasites were eliminated in 43.2% of cases on days 4-5 and in 56.6% on days 6-10. Metronidazole just on the second day of therapy caused parasitic elimination in 28.6% of the patients. All the patients were freed from lamblia within 5 days. Improvement occurred more rapidly with ecdisten treatment; immunological normalization was seen when ecdisten was used. Seven-ten-day course of ecdisten is sufficient for the treatment of primary lambliasis; when persistent lambliasis is treated, its course should be prolonged. If required, the course may be repeated, by increasing the daily dose.

Studies on the antidiarrhoeal activity of Aegle marmelos unripe fruit: validating its traditional usage.

BACKGROUND: Aegle marmelos (L.) Correa has been widely used in indigenous systems of Indian medicine due to its various medicinal properties. However, despite its traditional usage as an anti-diarrhoeal there is limited information regarding its mode of action in infectious forms of diarrhoea. Hence, we evaluated the hot aqueous extract (decoction) of dried unripe fruit pulp of A. marmelos for its antimicrobial activity and effect on various aspects of pathogenicity of infectious diarrhoea. METHODS: The decoction was assessed for its antibacterial, antigiardial and antirotaviral activities. The effect of the decoction on adherence of enteropathogenic Escherichia coli and invasion of enteroinvasive E. coli and Shigella flexneri to HEp-2 cells were assessed as a measure of its effect on colonization. The effect of the decoction on production of E. coli heat labile toxin (LT) and cholera toxin (CT) and their binding to ganglioside monosialic acid receptor (GM1) were assessed by GM1-enzyme linked immuno sorbent assay whereas its effect on production and action of E. coli heat stable toxin (ST) was assessed by suckling mouse assay. RESULTS: The decoction showed cidal activity against Giardia and rotavirus whereas viability of none of the six bacterial strains tested was affected. It significantly reduced bacterial adherence to and invasion of HEp-2 cells. The extract also affected production of CT and binding of both LT and CT to GM1. However, it had no effect on ST. CONCLUSION: The decoction of the unripe fruit pulp of A. marmelos, despite having limited antimicrobial activity, affected the bacterial colonization to gut epithelium and production and action of certain enterotoxins. These observations suggest the varied possible modes of action of A. marmelos in infectious forms of diarrhoea thereby validating its mention in the ancient Indian texts and continued use by local communities for the treatment of diarrhoeal diseases.

Impact of lactoferrin supplementation on growth and prevalence of Giardia colonization in children.

We conducted a randomized, double-blind, placebo-controlled trial comparing supplementation with bovine lactoferrin versus placebo for the prevention of diarrhea in children. Comparison of overall diarrhea incidence and prevalence rates found no significant difference between the 2 groups. However, there was a lower prevalence of colonization with Giardia species and better growth among children in the lactoferrin group.

The effect of blueberry extracts on Giardia duodenalis viability and spontaneous excystation of Cryptosporidium parvum oocysts, in vitro.

The protozoan parasites Giardia duodenalis and Cryptosporidium parvum are common causes of diarrhoea, worldwide. Effective drug treatment is available for G. duodenalis, but with anecdotal evidence of resistance or reduced compliance. There is no effective specific chemotherapeutic intervention for Cryptosporidium. Recently, there has been renewed interest in the antimicrobial properties of berries and their phenolic compounds but little work has been done on their antiparasitic actions. The effect of various preparations of blueberry (Vaccinium myrtillus) extract on G. duodenalis trophozoites and C. parvum oocysts were investigated. Pressed blueberry extract, a polyphenolic-rich blueberry extract, and a commercially produced blueberry drink (Bouvrage) all demonstrated antigiardial activity. The polyphenol-rich blueberry extract reduced trophozoite viability in a dose dependent manner. At 167 microgml(-1), this extract performed as well as all dilutions of pressed blueberry extract and the Bouvrage beverage (9.6+/-2.8% live trophozoites remaining after 24h incubation). The lowest dilution of blueberry extract tested (12.5% v/v) contained >167 microgml(-1) of polyphenolic compounds suggesting that polyphenols are responsible for the reduced survival of G. duodenalis trophozoites. The pressed blueberry extract, Bouvrage beverage and the polyphenolic-rich blueberry extract increased the spontaneous excystation of C. parvum oocysts at 37 degrees C, compared to controls, but only at a dilution of 50% Bouvrage beverage, equivalent to 213 microgml(-1) gallic acid equivalents in the polyphenolic-rich blueberry extract. Above this level, spontaneous excystation is decreased. We conclude that water soluble extracts of blueberries can kill G. duodenalis trophozoites and modify the morphology of G. duodenalis and C. parvum.

Water quality monitoring: the basis for watershed management in the Oldman River Basin, Canada.

The Oldman River flows 440 km from its headwaters in south-western Alberta, through mountains, foothills and plains into the South Saskatchewan River. Peak flows occur in May and June. Three major reservoirs, together with more than a dozen other structures, supply water to nine irrigation districts and other water users in the Oldman basin. Human activity in the basin includes forestry, recreation, oil and gas development, and agriculture, including a large number of confined livestock feeding operations. Based on the perception of basin residents that water quality was declining and of human health concern, the Oldman River Basin Water Quality Initiative was formed in 1997 to address the concerns. There was limited factual information, and at the time there was a desire for finger pointing. Results (1998-2002) show that mainstem water quality remains good whereas tributary water quality is more of a challenge. Key variables of concern are nutrients, bacteria and pesticides. Point source discharges are better understood and better regulated, whereas non-point source runoff requires more attention. Recent data on Cryptosporidium and Giardia species are providing benefit for focusing watershed management activities. The water quality data collected is providing a foundation to implement community-supported urban and rural better management practices to improve water quality.